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UDC 535.33A technique of layer-by-layer laser microanalysis of the materials of easel-painting works employing a twopulse scheme of substance excitation and registration of the spectrum from one double pulse is suggested. With paintings from the Nesvizh Portrait Gallery as examples, the effectiveness of the method in identification and attribution of paintings is shown.Keywords: pigments, layer-by-layer laser spectrum microanalysis, double pulse.Introduction. At the present time, in studying paintings, methods of art expertise are more often supplemented with methods of natural sciences. Comprehensive technical-technological investigation of a work of art that encompasses each structural element of the picture (base, primer, drawing, paint layer, protective coating) includes overall examination of the work by luminescent methods on exposure to UV and IR irradiation and by the x-ray graphical method as well as studying the paint materials used. The materials used in painting a picture are very diverse and are determined by the time of creation of a picture, the tradition of the artistic school, and also by the artistic individuality of a painter -his style and technique. Accumulation of information on the materials that were used at different times by various painters and the creation of a database are essential for the success of the investigations carried out.The most difficult problem in studying a work of art is determination of the pigments and binders that enter into the primer and paint layers. Pigments are identified by methods of microchemical analysis, petrography, and various physical methods, for example, x-ray structural analysis, as well as different kinds of spectral analysis (IR Fourier spectroscopy to identify the binder and an emission analysis to identify pigments). The x-ray structural analysis has some limitations because the intensity of a spectrum depends on substance absorption, which, in turn, influences the sensitivity of the method. Therefore, registration of even a relatively high content of pigment with low absorptivity is difficult when this pigment is mixed with a highly absorptive component [1]. The spectral electric-discharge emission method allows one to rather exactly determine the chemical composition of a sample but needs a great amount of it. Moreover, it is extremely difficult to perform a layer-by-layer analysis by this method.In the present work, we suggest a method of two-pulse laser spectrum microanalysis of the chemical composition of easel-painting materials. Its advantage over the electric-discharge method of spectral analysis lies in the fact that it needs no special preparation and it is local and provides the possibility of layer-by-layer examination of the chemical composition of the materials of the work studied.Experimental Technique. Model samples have a multilayer structure with known chemical composition of each layer. As the base for the two samples prepared by us, a linen canvas was used primed by titanium white on an oil binder. The paint layer of the first...

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